1. Field of the Invention
The present invention relates to a reflector suitable for a lighting apparatus which uses a plurality of light-emitting elements such as LEDs, and to a lighting apparatus including the reflector.
2. Description of the Related Art
Recently, lighting apparatus which uses a plurality of light-emitting elements such as LEDs as light sources have been developed. For lighting apparatus of this type, there has been an increasing demand of increasing their outputs, and also a tendency of increasing light-emitting element employed in the apparatus. Further, such lighting apparatus which employs a plurality of light-emitting elements is equipped with a reflector for efficiently controlling luminous intensity distribution of light from each light-emitting element. There is a tendency that such a reflector is increased in size as the number of light-emitting elements employed is increased.
Reflectors are subjected to heating and cooling by heat from the light sources as the lighting apparatus is turned on and off, and they repeatedly undergo thermal expansion and thermal contraction. For this reason, reflectors are easily warped or deformed due to heat, and if the reflection surfaces are deformed, it is no longer possible to perform desired luminous intensity distribution control.
Although it is not a case of a reflector, lighting apparatus in which a light transmitting lens body formed into a thin column is used as means for controlling luminous intensity distribution of light emitted from light from a plurality of LEDs has been known. (For example, see Jpn. Pat. Appln. KOKAI Publication No. 2006-172895.) The lens body disclosed in this publication includes a plurality of recess portions which correspond to a plurality of LEDs, and it transmit light emitted from these LEDS and performs the luminous intensity distribution control.
However, this publication makes no mention of means for assuring the desired luminous intensity distribution control by preventing the warpage and deformation of the lens body caused by heat.